Transmitter supply source



Feb. 27, R VILLEM r AL TRANSMITTER SUPPLY SOURCE Filed July 16, 1930 1 V I1 TRANSMYI'TER p PLATE SOURCE r a 1 E5 1: :I' 7 M 2 I I I Q15. i Asscima PL}! 75 SOURCE INVENTOR RAYMOND V\LLEM AT'TORNEY BY TWQW Patented Feb. 27, 1934 7 1,949,263 TRANSMITTER SUPPLY sonnet:

Raymond Villem and Roger Aubert,

Paris,

France, assignors to Compagnie Generale de Telegraphic sans Fil, Paris, France, a corporation of France Application July 16, 1930, Serial No. 468,278 In France July 18, 1929 9 Claims.

The present invention relates to telegraphy systems, and in particular to telegraphy systems including thermionic relay tubes which are keyed to produce telegraph signals, and includes means for regulating the load of the system on the power sources necessary to energize the tubes. Such regulation permits increased keying speed to be attained.

The sending is efiected, in certain types of 10 transmitters, comprising amplification stages, by impressing on the grids of the tubes of one of the amplification stages a suificiently high negative potential in order to block all oscillations in the plate circuits. Hence, during the sending of a blank letter i. e. a space or no signal the consumption of this stage drops to zero. The transmitter being regulated for the functioning by impulsion, the consumption of the following stages drops likewise to zero.

During the sending at high speed, the plate sources of these diiierent stages are accordingly subjected to a very severe service having to pass suddenly and at high frequency from the idling course to the operating course. Besides the exhaustion to which the sources are subjected, the self-induction of the generators and their capacity with respect to the earth as well as the selfinduction and the capacity of the filter cells tend to oppose a rapid variation of the operations and tend to limit the sending speed.

According to the invention this inconvenience is met by reducing the relative variation of the charge of the generators. The means to be employed thereby may however vary according to the cases.

If the power furnished by the source is not too large (stages of small or medium power) it is sent permanently through a resistance R. Designating by i the current in this resistance and by I the current of normal charge, the relative variation of charge is then only (I +1) /i instead of I/O. This arrangement presents beside the advantage of a considerable reduction in the troublesome effects of the above mentioned self-inductances and capacities.

In the high power transmitters (for instance kw.) this method is advantageously applied to the generator feeding the stage of medium power (1 kw. for instance) on which the sending takes place. This generator feeds permanently to a resistance R. It further furnishes the plate current of all the small stages in the manner that, during the sending, the output power varies not more than For the high power stages, the energy furnished by the source attains a considerable value and the application of the previous method would lead to an absolutely inadmissible permanent dissipation of energy.

In this case the operation is preferably done as 0 follows:

During the sending of blanks i. e. spaces or no signal there is absorbed by means of special tubes, called absorption tubes, the power which the source supplies normally to the oscillator during the sending of a dash. These tubes, if it is a case oi a mixed telegraph-telephone station may be in practice the same tubes used for the modulation in telephony and which are not used in telegraphic transmission.

The output variation of the source is thus rendered Zero and the sending may be pushed to very high speeds. The device according to the invention is rendered efiicient by a system of tube relays representing the means for passing instan- 7 taneously the charge of the oscillator to the absorption tubes and vice versa. The system also allows the regulation of the percentage of the energy compensated so that it may be operated with variable output from the source at low speed 30 and with constant output from the source at high speed. For an intermediate speed, the output variation may be regulated for any value desired.

A better understanding will be had from the drawing from the following detailed description of the invention and, therefrom when read in connection with the attached drawing, in which,

Figure 1 shows for purposes of illustration apparatus for power supply regulation; while,

Figure 2 shows a modification of the arrangement of Figure 1.

The assembly of the control is shown in Fig. 1 wherein 1 and 2 are two relay tubes with three electrodes whose heating circuit, independent of the heating circuits of the other tubes of the installation, is supplied by means of a transformer T. The plate potential of tube 1 is furnished by a generator S1. The potential for the plate circuit of tube 2 is furnished by a generator S2. These generators are shunted as shown by resistances Bi and R5 respectively for the reason explained hereinbefore. The negative pole of the source S2 is connected, as shown, to the grids 6 and 8 of the absorption tubes 5 and 7. The return of the plate current of tube 2 to the cathode or more exactly to the midpoint of the secondary of supply transformer T is accomplished by the intermediary of a resistance R2, the return of the plate current of tube 1 traverses first a resistance R1, then a complex assembly of circuits consisting of, a generator S3 which may be used for supplying the polarizing potentials of the grids of the different stages of the oscillator tubes 9 and 11, a general potentiometer P located at the terminals of the said generator S3, a resistance 3. The positive pole of the generator S3 is grounded at M (which is also a common point for the heating circuit of the tubes of the installation other than 1 and 2). A resistance R3, of large value in comparison to P and 3 shunts the assembly S3, 3. To this resistance R3, at a point N close to the connection leading directly to the heating circuit of 1 and 2 is connected one of the contacts of the sending relay, the other contact of this relay is joined to the grid of tube 1 while furthermore a permanent connection is established between grid of tube 1 and another point 0 taken on resistance R3 and farther away than point N from the connection to the heating circuit.

The object of this arrangement is to obtain, with a single contact A, so as to avoid the dead intervals, at g1 connected with the grids 10 and 12 of the oscillator tubes 9 and 11 and at G2 connected with the grids 6 and 8 of the absorption tubes 5 and 6 respectively two negative potentials, the first being small when the second is high and vice versa. The object is attained in the following manner: The potentials are collected in the plate circuits of the two tubes 1 and 2, the polarization of the grid of tube 2 being controlled by the plate current of tube 1 and the polarization of the grid of tube 1 being controlled by the sending key A.

The operation is as follows: at a blank period of sending the key A is closed; the grid in of tube 1 is impressed to a small negative tension which is the one corresponding to the ohmic drop in a small portion of resistance R3. The plate current I1 in tube 1 is large, it produces in the reresistance R1 a great potential drop and the grids 10 and 12 of the oscillators 9 and 11 respectively are subjected to a high negative potential which blocks all oscillations in the plate circuits of the oscillation generators.

The current I1 when traversing resistance 3 produces a potential drop which polarizes negatively the grid 92 of tube 2. The plate current I2 is then very small; the potential drop along R2 is itself very small and the polarization of grids 6 and 8 of the absorption tubes 5 and '7 is not very high, the absorption tubes absorb the energy which the source furnished previously to the oscillator.

In the period of the sending of a dash, key A is open and inverse phenomena takes place.

Grid 91 of tube 1 is brought to a greatly negative potential, the anode current I1 of tube 1 is zero; the grids l0 and 12 of the oscillators 9 and 11 are therefore polarized normally and the transmitter oscillates normally; grid oz of tube 2 is slightly negative only, the anode current I2 of tube 2 is large and the negative potential impressed on grids 6 and 8 of absorption tubes 5 and '7 is very large; the absorption tubes no longer absorb any power.

Attention is called to the fact that the composite power is regulated by the simple manipulation of resistance 3.

The above device comprises the use of two supplementary generators S1 and S2 whose windings are impressed with a variable potential with respect to the earth, at the sending frequency. The following variant has the advantage of the absence of any supplementary generator and to have no body with a variable potential. The sending speed may then attain very high values.

This variant is represented in Fig. 2 in which the same letters or numbers of reference designate the same elements as in Fig. 1. It may be seen that this second arrangement provides for the use of a single generator S3 for supplying at the same time the general potentiometer P and the plates of tubes 1 and 2. The sending contact A is shunted by a resistance Re.

In all these connections, the generator and resistance assemblies may be replaced by accumulator batteries, if need be with multiple taps.

The invention lends itself to numerous applications and constructional variations in addition to those given solely by way of example and not limitative.

We claim:

1. The combination with a work circuit com prising thermionic tubes supplied with potential from a source, of means for insuring a constant drain on said source during periodic operation of said tubes comprising, absorber tubes having their anode circuits connected with said source, and means for rendering said absorber tubes alternately conducting and non-conducting as said work circuit becomes deenergized and energized during periodic operation of said tubes including, a thermionic keying tube having its anode electrode connected by way of a source of potential and a resistance network to its cathode, a connection between said resistance network and the control electrodes of said tubes in said work circuit, a second thermionic keying tube having its control electrode connected to a different point on said resistance network, a resistance connected between the anode and cathode of said last named keying tube, a connection between a point on said resistance and the control electrodes of said absorber tubes, and a key connected in parallel with a portion of said resistance network and to the control electrode of said first named keying tube.

2. The combination with a telegraphy circuit including thermionic tubes having their output electrodes supplied with potential from a source, of means for insuring a constant drain on said source during telegraph keying of said circuit comprising, absorber tubes having their anode circuits connected with said source, and means for rendering said absorber tubes alternately conducing and non-conducting as said circuit is keyed including, a pair of thermionic control tubes each having its anode electrode connected by way of a SOlllCQ of potential and a resistance to its cathode electrode, a connection between one of said resistances and the control electrodes of the tubes in said telegraphy circuit, a connection between the other of said resistances and the control electrodes of said absorber tubes, means for normally biasing one of said control tubes to a point at which it is non-conductive, means for normally biasing the other of said control tubes to a point at which it is conductive, said biasing means being connected to a resistance network in turn connected with said resistances in the anodes and cathodes of said control tubes, and keying means connected with one of said biasing means for varying the conductivity of said control tubes in opposite and conjugate relation.

3. The combination with a work circuit comprising a thermionic tube connected with a load circuit which varies and is supplied with poten tial from a source, of means for insuring a constant drain on said source during variations in the load comprising, an absorber tube having its anode circuit connected with said source, and means for rendering said absorber tube more conducting when said load decreases and less conducting when said load increases including, a pair of thermionic keying tubes having their anode electrodes connected by way of resistances to their cathodes, a connection between one of said resistances and the control electrodes of the tube in said work circuit, a connection between the other resistance and the control electrode of said absorber tube, and means including a connection between the control electrode of the said keying tubes and a resistance network which includes one of said first resistances for varying the conductivity of said keying tubes in opposite and conjugate relation.

4. The combination of a high power thermionic oscillation generator having an anode circuit including a source of potential and a control grid circuit, of an absorber tube having an anode circuit connected with said source of potential and a control grid circuit, of means for rendering said absorber tube conductive when said oscillator tube is non-conductive to maintain a constant drain on said source comprising, a pair of thermionic control tubes having a common cathode heating circuit, a resistance network connected between the anodes of said tubes and to the common cathode heating circuit, means for applying potential to said resistance network, a connection between the control electrode of each of said tubes and said resistance network, said connections being made at points of diiierent potential on said network, a key connected in shunt with a portion of said resistance network, s id arrangement being such that when said key is closed the control electrode of one of said control tubes is biased to render said tube conductive and the control grid of the other of said control tubes is biased to a point such that said tube is non-conductive, a connection between a point on the anode circuit of one of said tubes and the control electrode or" said oscillation generator, and a connection between a point on the anode circuit of the other of said tubes and the control electrode of said absorber.

5. The combination of a thermionic oscillation generator having a variable load circuit connected to a source of potential and a control grid circuit, of an absorber tube having an anode circuit connected with the source of potential and a control grid circuit, of means for rendering said absorber tube more conductive when said load decreases and less conductive when said load increases to maintain a constant drain on said source comprising, a pair of thermionic control tubes, a resistance network connected between the anodes of said tubes and to the cathodes thereof, a biasing network connected to the control electrodes of said control tubes to normally render one of said control tubes conductive and the other non-conductive, keying means in said biasing network for altering said condition, a connection between a point on the anode circuit of one of said control tubes and the control electrodes of said oscillator, and a connection between a point on the anode circuit of the other of said control tubes and the control electrode of said absorber.

6. In a telegraph transmitter including, a thermionic transmitter tube having a work circuit connected with a source of potential, means for maintaining a constant load on said source of potential during keying of said transmitter including, a circuit of variable impedance connected to said source of potential, and means for lowering the impedance in said circuit when spacing currents flow in said work circuit and for increasing the impedance of said circuit when marking currents flow in said work circuit comprising, a pair or thermionic control tubes, each of said control tubes having an anode circuit including, resistances, a connection between the anode circuit of one of said control electrodes and the control electrode in said transmitter tube, means for utilizing the potential drop in the resistance in the other anode circuit for varying the impedance of said absorption circuit, and a resistance network interconnecting the control electrodes of said control tubes and connected to said first named resistances for rendering one of said tubes conducting when the other is nonconducting, and vice versa.

'7. The combination with a telegraph transmitter having a thermionic tube connected with a variable load and with a source of potential, of means for maintaining the drain on said source constant during variations of the load comprising, in combination, an absorber tube having its anode circuit connected to said source, a pair of three-electrode vacuum tubes, common heating means connected with the cathodes thereof, a resistance shunted plate generator connected by way of resistances between the anode and cathodes of said tubes, a slidable contact on the resistance in shunt with said generator, said contact being connected with the grid circuit of one of said three-electrode tubes and by way of a variable resistance to the cathode of said tube, a key connected in parallel with a portion of said resistance, a connection between the grid of the other of said tubes and said key, a connection between the anode circuit of one of said triodes and the control electrode of said transmitter tube, and a connection between the anode circuit of the other of said triodes and the control electrode of said absorber tube.

8. In apparatus of the character described, a power tube, a keying tube having keying means in its input circuit and a connection between its output circuit and said power tube for controlling the output thereof, an absorber tube having its output circuit connected in parallel with the output circuit of the power tube, an impedance in the output circuit of the keying tube, and a connection between said impedance and the input circuit or" the absorber tube, whereby said absorber tube is rendered conductive when the power tube is rendered non-conductive, and vice versa.

9. In apparatus of the character described, a power tube, a keying tube coupled thereto for controlling the output thereof, an absorber tube paralleling the power tube, and a resistance in the output circuit of the keying tube, said resistance being coupled to the absorber tube in a fashion such that the absorber is rendered conductive as the power tube is rendered non-conductive, and vice versa.

RAYMOND VILLEM. ROGER AUBERT. 

